Boiler

ABSTRACT

A boiler assembly comprises a boiler with an associated domestic water heater arranged below the boiler in a common enclosure, the heating water supply pipe to the heater leading from an upper region of the boiler to a lower region of the heater, the heating water return pipe leading from an upper region of the heater to a lower region of the boiler. A circulation pump is provided in the heating water circuit.

ite States Patel;

Inventor Hans Viessmann Battenberg/Eder, Im Hain, Germany Appl. No. 623 Filed Jan. 5, 1970 Patented Dec. 7, 1971 Priority Jan. 4, 1969 Germany P 19 01 438.1

BOILER 6 Claims, 2 Drawing Figs.

U.S. Cl 122/406 1R, 126/362 Int. Cl F22d 7/00 Field of Search 122/33, 37

[56] I References Cited UNITED STATES PATENTS 1,959,933 5/1934 Simsohn 237/19 X 1,963,624 6/1934 Kroger 122/37 2,190,382 2/1940 Moore 237/19 2,554,338 5/1951 Levine 122/37 X 3,007,457 11/1961 Ospelt 122/37 3,437,078 4/1969 Olson 122/37 Primary Examiner- Kenneth W. Sprague Attorney-l(urt Kelman ABSTRACT: A boiler assembly comprises a boiler with an associated domestic water heater arranged below the boiler in a common enclosure, the heating water supply pipe to the heater leading from an upper region of the boiler to a lower region of the heater, the heating water return pipe leading from an upper region of the heater to a lower region of the boiler A circulation pump is provided in the heating water circuit.

PATENTEUBEE nan 3.625187 SHEET 1 0F 2 layer; lor: RM/S V IESSM WV BOILER This invention concerns improvements in or relating to boilers having an associated domestic water heater system in the form of a tank heater and/or a continuous flow heater, such units being installed in a common boiler enclosure.

Such boilers are already known. The heat exchanger for domestic water heating is generally located above or beside the combustion chamber of the boiler and further more may either by incorporated in the boiler water chamber or be mounted as a separate unit on the boiler and connected to the boiler by means of hot water pipes; this applies in particular in cases where the heat exchanger is a heater and not a continuous flow heater.

To accelerate the heating in the water heater it is usual to incorporate a circulating pump, also known as a charging pump, in the hot water pipes. It is then possible to regulate the temperature of the domestic water to be heated, i.e. the hot water, by means of the charging pump. To this end a thermostat is installed in the water heater which actuates the pump on the water temperature falling below the desired value and shuts off the pump on reaching the desired value.

The regulation of the hot water temperature, i.e. an upward limitation of the hot water temperature, can be important for various reasons, such as for example when the water is corrosive. If galvanized steel pipes are used as the hot water pipes, by limiting the hot water temperature to for example 65 C. the corrosive action of the'water is reduced. If the water is very hard, by limiting the hot water temperature the precipitation of salts in the water heater and the hot water pipes connected on the outlet side can be reduced.

With the present-day water conditions corrosion problems are becoming increasingly difficult. Galvanized steel pipes can only be used in certain areas and in many areas the water corrodes iron materials. Hot water pipes made from copper could be used to advantage but copper prices are generally extraordinarily high. Therefore, in general, such a high price for copper pipes acts as a deterrent to their use.

Plastic pipes are corrosionproof relative to drinking water but are sensitive to temperatures above 60 C. An upward limitation of the boiler temperature is absolutely necessary with plastic hot water pipes.

Apart from this, with the arrangement of water-heaters and countercurrent equipment above or at the side of the boiler a nonretum valve is necessary to prevent an undesirable heating of the water heater due to gravity circulation on switching off the charging pump.

If the water heaters are located at the top of the boiler or above the boiler the domestic water assumes almost the same temperature as the heating water. Generally, such hot water can not be used for washing or the like, so cold water must be mixed therewith, thus requiring additional apparatus. In addition, such heated water again causes corrosion in the pipes connected on the output side.

Hitherto the hot heating water was supplied at the top of the water heater from the hot water boilers and led away again at the bottom, resulting in the domestic water in the heater assuming a high temperature. The disadvantage is, however, that the AT, i.e. the temperature difference between the heating water supplied and the domestic water to be heated is relatively small if the heating water is supplied at e.g. 85 C. and the domestic hot water has a temperature of 70 or 75' C. Heating takes longer due to the small AT.

The object of the present invention is to solve this overall problem of not producing the hot domestic water at too high a temperature. According to the invention there is provided a boiler assembly comprising a boiler with an associated domestic water heater system housed in a common boiler enclosure, such boiler including a combustion chamber, combustion gas flues and enclosing water jacket, wherein the heater system is arranged below the boiler and the boiler, and heater system are connected by means of circulation pipes, the heating water supply pipe to the heater system leading from an upper region of the boiler to a lower region of the heater system, the heating water return pipe from the heater system leading to a lower region of the boiler from an upper region of the heater system and a circulation pump being provided in the heating water circuit.

Two or more domestic water heaters may be provided, the or each such heater possibly comprising a tank heater or a continuous flow heater. In the event of a plurality of heaters being provided, one or more may be a tank heater and one or more a continuous flow heater.

The circulation pump is preferably provided in the heating water supply pipe to the heater(s), and a thermostat should generally be provided, which is adapted to shut off the pump upon the domestic water reaching a desired temperature.

For supplying heating water to the domestic water heater in such an assembly the circulating pump is used, which, via the pipes, draws the hot water from the upper region of the boiler and forces it down into the lower region of the domestic water heater system. If the domestic water has reached the desired temperature, the thermostat in or on the water heater system shuts off the pump.

The assembly according to the invention is not only advantageous due to the possibilities of regulation and the elimination of the nonretum valves hereinbefore mentioned but also because it has been found that, by guiding the heating water flow downwards, the heat absorption can be increased by increased flow rate of the heating water. The feeding of the heating water from below is advantageous because thereby the heating water reaches the region of the boiler where the domestic water temperature is always lowest, i.e. where the AT is greatest.

In order that the invention may be readily understood, an embodiment thereof will now be described by way of example and with reference to the accompanying diagrammatic drawings in which:

FIG. 1 is a front view of the boiler assembly and FIG. 2 is a side view of the boiler assembly shown in HO. 1.

The drawings are only intended to clarify the circuit and arrangement principles according to the invention so that no structural details of the boiler and domestic water heater are given, these being known details. In connection with the invention it is unimportant in which way the heat in the boiler is produced and transferred to the heating medium.

Referring to the drawings there is shown a boiler assembly comprising a boiler 1 which includes in known manner a combustion chamber, combustion gas flues and an enclosing water jacket, a pair of domestic water tank heaters 2, arranged below the boiler l, and a domestic water continuous flow heater 3 providing countercurrent water flow, these units being housed in a common boiler housing 4.

The hot water for heating the water in the domestic water heaters is fed to the heater by means of supply pipe 6, which leads from an upper region of the boiler l to a lower region of the heaters 2. A circulation pump 7 connects water supply pipe 6 to pipes 8 to deliver hot water from boiler l to the lower region of heaters 2. The inlets of the pipes 8 to the water heaters are indicated at 9 in FIG. 1.

Heating water return flow pipes 5 lead from an upper region of the heaters 2 to a lower region of the boiler l.

A thermostat may be provided in assembly, which is adapted to shut off circulation pump 7 upon the domestic water in tank heater 2 or continuous flow heater 3 reaching a desired temperature.

I claim:

1. A boiler assembly comprising 1. a common enclosure,

2. a boiler for heating water arranged in the common enclosure and a. a combustion chamber in the boiler for heating the water therein,

3. a domestic water heater system arranged in the common enclosure below the boiler, and

4. water conduit means interconnecting the boiler and the domestic water heater system, the conduit means includmg the water heaters is a tank heater.

4. The boiler assembly of claim 2, wherein at least one of the water heaters is a continuous flow heater.

5. The boiler assembly of claim 2, wherein the domestic water heater system comprises a pair of tank heaters and a continuous flow heater.

6. The boiler assembly of claim 1, wherein the circulation pump is mounted in the water supply pipe. 

1. A boiler assembly comprising
 1. a common enclosure,
 2. a boiler for heating water arranged in the common enclosure and a. a combustion chamber in the boiler for heating the water therein,
 3. a domestic water heater system arranged in the common enclosure below the boiler, and
 4. water conduit means interconnecting the boiler and the domestic water heater system, the conduit means including a. a water supply pipe leading from an upper region of the boiler to a lower region of the heater system, b. a return pipe leading from an upper region of the heater system to a lower region of the boiler, and c. a water circulation pump in the conduit means for circulating the water between the boiler and the heater system.
 2. a boiler for heating water arranged in the common enclosure and a. a combustion chamber in the boiler for heating the water therein,
 2. The boiler assembly of claim 1, wherein the domestic water heater system comprises a plurality of water heaters.
 3. The boiler assembly of claim 2, wherein at least one of the water heaters is a tank heater.
 3. a domestic water heater system arranged in the common enclosure below the boiler, and
 4. water conduit means interconnecting the boiler and the domestic water heater system, the conduit means including a. a water supply pipe leading from an upper region of the boiler to a lower region of the heater system, b. a return pipe leading from an upper region of the heater system to a lower region of the boiler, and c. a water circulation pump in the conduit means for circulating the water between the boiler and the heater system.
 4. The boiler assembly of claim 2, wherein at least one of the water heaters is a continuous flow heater.
 5. The boiler assembly of claim 2, wherein the domestic water heater system comprises a pair of tank heaters and a continuous flow heater.
 6. The boiler assembly of claim 1, wherein the circulation pump is mounted in the water supply pipe. 